Pipe couplings are used to couple or join the ends of two lengths of pipe together. Pipe couplings are basically sleeve-like devices, having a cylindrical passage therethrough for receiving the two pipes. In addition to coupling the ends of the pipes together, a pipe coupling provides seals around each pipe end for preventing leakage from the joint.
A typical application of pipe couplings occurs when a damaged section of pipe is replaced. A new pipe section is inserted in place of the old damaged section. Pipe couplings are used on each end of the new section of pipe to couple the section to the free ends of the in situ pipe.
In the prior art, flexible pipe couplings have been used to couple pipes together. Flexible pipe couplings typically have sealing surfaces integral therein, simplifying both manufacturing and installation. In addition, flexible pipe couplings flex with pipe movement to maintain the integrity of the seals around the pipes. Such pipe movement occurs when the surrounding earth moves. Occasionally pipe movement can be such that shear forces are produced across the pipe joint. Therefore, it is desirable to have a pipe coupling that will withstand such shearing forces.
In addition, it is desirable to use one type of pipe coupling for both sewer pipes and high pressure water pipes. In contrast to high pressure water pipes, sewer pipes are typically low pressure applications. The pipe coupling should be reinforced to prevent harmful bulging of the pipe coupling due to the high water pressure exerted by high pressure water pipes. Furthermore, should the pipe coupling be deformed, the reinforced pipe coupling should be able to regain its original shape after the deforming force is removed.